Initial program load system

ABSTRACT

This invention provides an initial program load system wherein, even when one IPL device has gone wrong, other IPL devices are automatically operated in succession instead of the faulty IPL device, whereby the automatic restoration of a whole system including the IPL system is prevented from being delayed by the fault of the IPL device.

BACKGROUND OF THE INVENTION

This invention relates to an initial program load (hereinbelow,abbreviated to "IPL") system which loads an electronic computer systemwith its initial program.

A prior art IPL system has been as shown in FIG. 1. Referring to thefigure, numeral 1 designates a central processing unit (hereinbelow,abbreviated to "CPU"), numeral 2 a switch which is built in the CPU 1and which appoints an IPL device, numerals 3 and 4 magnetic disc devicesrespectively, and numeral 5 a magnetic tape device. In the followingdescription, it is assumed that the initial program is stored in themagnetic disc device 3, namely, that the magnetic disc device 3constructs the IPL device. FIG. 2 is a flowchart which shows the flow ofIPL operations in the prior art, and in which numerals 20-24 indicaterespective steps.

In general, the IPL operations are started by manually actuating the IPLswitch. However, in a case where power supply to the computer system hasturned "off" for any reason and has thereafter been restarted, the IPLoperations are automatically performed. More specifically, the IPLoperations are started at the step 20 in FIG. 2. The IPL device 3 is setto start by the step 21, so as to read out the initial program and theIPL operations store it in the CPU 1. At the subsequent step 22, whetheror not the readout operation has been normally executed is decided bychecking the status of the CPU 1 after the readout, or it is decideddepending upon whether or not there is a response from the the IPLdevice 3 within a predetermined period of time since the start of thereadout has been set. When the result of the decision at the step 22 isNO, the operating flow shifts to the step 23, which stops the computersystem.

Only in a case where the result of the decision at the step 22 is YES,the operation of the computer system is started by the initial program.That is, under the control of the initial program loaded first, the nextprogram is loaded. This corresponds to the step 24. Before the IPL hasbeen executed, any information is not produced at all, and hence, anyprogram to be utilized does not exist till the end of the load of theleast required information. Therefore, the computer system needs to beprocessed by hardware till then. Accordingly, when the IPL device isabnormal, the continuation of the processing is impossible, and theoperating flow cannot avoid shifting to the step 23. Moreover, in somekinds of abnormalities, the computer system repeats the above processingwithout stopping.

The procedure of the prior art IPL is as stated above. In order to startthe IPL again after the step 23, the manual operation must be resortedto. In addition, in a system which is expected to automatically returnto normalcy from the momentary interruption of a power source; when thestep 23 has been reached due to any fault of the IPL device, theintervention of the manual operation is indispensable. This leads to thedisadvantage that, in cases of an unmanned operation etc., it takes avery long time before the system is restarted.

SUMMARY OF THE INVENTION

This invention has been made in order to eliminate the disadvantages ofthe prior art system as described above. That is, the invention has forits object to provide an IPL system wherein even when one IPL device hasgone wrong, one or more different IPL devices operate instead of thefaulty IPL device in successive fashion, so that the automaticrestoration of a whole system including the IPL system is not delayed bythe fault of the IPL device.

In one aspect of performance of this invention, an IPL system comprisesthe first load step of stating automatically under a predeterminedcondition and loading a computer with an initial program from a firstdevice among a plurality of nonvolatile memories each storing theinitial program, the second load step of loading the computer with theinitial program from a second device among said plurality of nonvolatilememories when any fault has been detected in said first load step orwhen the load operation does not end within a predetermined period oftime, and the step of loading the computer with the initial program bysuccessively using remaining devices among said plurality of nonvolatilememories, when any fault has been detected in said second load step orwhen the load operation does not end within a predetermined period oftime.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram for explaining a prior art initial programload system;

FIG. 2 is a flowchart showing the flow of operations in the prior artsystem;

FIG. 3 is a block diagram explaining embodiment of an initial programload system according to this invention; and

FIG. 4 is a flowchart showing the flow of operations in the system ofFIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Now, the system of this invention will be described with reference tothe drawings. FIG. 3 is a block diagram which shows an embodiment ofthis invention, and in which the same symbols as in FIG. 1 denote thesame or corresponding parts. The IPL devices appointing switch 2 iscomposed of a first switch 2a and a second switch 2b. In the arrangementof FIG. 3, the magnetic disc device 3 constructs a first IPL device,while the magnetic disc device 4 constructs a second IPL device. Theswitch 2a appoints the first IPL device 3, while the switch 2b appointsthe second IPL device 4. FIG. 4 is a flowchart which shows the flow ofoperations in the system of this invention, and in which the samenumerals as in FIG. 2 indicate the same or corresponding steps. Numerals41, 42 and 43 indicate steps added anew. At the step 21 in FIG. 4, thefirst IPL device 3 is set to start by the IPL devices appointing switch2a. The operations of the steps 20, 21 and 22 are similar to those inthe case of FIG. 2. In a case where the result of the decision at thestep 22 is NO, the second IPL device 4 is set to start by the IPLdevices appointing switch 2b, to shift the operating flow to the steps41 and 42. When the result of a decision at the step 42, which decidesif the second IPL device 4 is normal, is NO, the operating flow shiftsto the step 23 for the first time so as to stop the computer system. Ineither case, the IPL device having succeeded in the IPL operations isrecorded at the step 43. The same initial program are stored in thefirst IPL device 3 and the second IPL device 4. As understood bycomparing FIG. 2 with FIG. 4, in this invention, the step 23 is reachedto stop the system only in the case where the decisions are NO at boththe steps 22 and 42. The probability of occurrence of this case is muchlower than that of the case where the decision of NO is made only at thestep 22.

Although, in the above embodiment, the steps 20, 21, 22, 41, 42, 23 and43 have been described as the hardware operations, they may of course becontrolled with a microprogram. In addition, although the use of themagnetic disc devices 3 and 4 as the IPL devices has been exemplified,other magnetic memories, a card reader with cards, etc. may be used aslong as they are nonvolatile memories. It is also possible to constructdifferent IPL devices by employing different memory areas within anidentical magnetic disc device. Further, the IPL devices storing thesame initial programs may be disposed in any number.

Besides, the operations illustrated in FIG. 4 can be preset withoutdisposing the IPL appointing switches 2a and 2b shown in the embodiment.

As set forth above, according to this invention, the initial program ofa system is stored in a plurality of IPL devices, so that thepossibility of the automatic restoration of the system from themomentary interruption of a power source can be remarkably enhanced. Inaddition, system-down attributed to local faults can be prevented as faras possible, and a computer system having a high rate of operation canbe provided.

What is claimed is:
 1. An initial program load system comprising thefirst load step of starting automatically under a predeterminedcondition and loading a computer with an initial program from a firstdevice among a plurality of nonvolatile memories each storing theinitial program, the second load step of loading the computer with theinitial program from a second device among said plurality of nonvolatilememories when any fault has been detected in said first load step orwhen the load operation does not end within a predetermined period oftime, and the step of loading the computer with the initial program bysuccessively using remaining devices among said plurality of nonvolatilememories, when any fault has been detected in said second load step orwhen the load operation does not end within a predetermined period oftime.
 2. An initial program load system according to claim 1 whereinsaid plurality of nonvolatile memories are nonvolatile storage deviceseach of which stores the initial program.
 3. An initial program loadsystem according to claim 1 wherein said plurality of nonvolatilememories are different memory areas of a single nonvolatile storagedevice, the initial program being stored in each of said memory areas.4. An initial program load system comprising the first load step ofstarting automatically under a predetermined condition and loading acomputer with an initial program from a first device among a pluralityof nonvolatile memories each storing the initial program, the secondload step of loading the computer with the initial program from a seconddevice among said plurality of nonvolatile memories when any fault hasbeen detected in said first load step or when the load operation doesnot end within a predetermined period of time, the step of loading thecomputer with the initial program by successively using remainingdevices among said plurality of nonvolatile memories, when any fault hasbeen detected in said second load step or when the load operation doesnot end within a predetermined period of time, and the step of recordingthat device among said nonvolatile memories which has succeeded in theinitial program load operation.